The use of cellular telephones and wireless networks has become increasingly widespread. As the use of cellular telephones has increased, the number and quality of additional features made available with the cellular telephones has also increased. For example, many mobile stations (i.e., cellular telephones) now provide chat applications, such as a Push-To-Talk service, for example. Push-to-Talk (PT) service is a “walkie-talkie” type of feature that allows a mobile station user to communicate with another mobile station user (or users) by pushing a single button on the cell phone.
Chat applications, such as Push-To-Talk (PTT) service, are useful for situations in which a user wants or needs to communicate with the same person or group of people repeatedly but not continuously. For example, a group of people at a mall may desire to keep in touch with each other after they split up to shop separately. Using Push-To-Talk, one person may quickly contact another person or other people without having to make a conventional cellular phone call.
The parties involved must first establish a PTT service between their respective phones. The wireless network is then aware of the presence of each mobile station (e.g., cell phone) involved in the PTT service, although no traffic channels are set up. The mobile stations initially communicate with the base stations of the wireless network using only overhead control channels to establish the PTT service. Once the PTT service is established, the call originator does not have to dial the number of the called party in order to communicate. The call originator only needs to press a button, wait for a beep (or a similar indicator), and then speak. Advantageously, many service providers do not charge these conversations against the users' allotted usage minutes for the cellular telephones.
Many conventional wireless network, such as code division multiple access (CDMA) systems, are designed under a switched voice model. Therefore, a set-up time of several seconds is deemed acceptable to user expectations. However, as CDMA and other conventional wireless protocols are increasingly used for time-sensitive services, faster call set-up times are required. As CDMA and other protocols have evolved to serve packet data needs, the paging procedures of those protocols have changed only slightly. As a result, the paging delays experienced in CDMA2000 packet data sessions are detrimental to user latency and network efficiency.
Currently, in CDMA2000 systems, the time set-up for real-time services such as chat includes the delays associated with the call originator sending the request to the base station, the base station sending the request to the chat server, the target base station paging the target mobile station, and the target mobile station acknowledging receipt of the paging message. One of the largest delays in this string of transactions is the time required for paging the target mobile station and for the target mobile station to acknowledge with a page response message. This delay alone may consume up to 500 milliseconds.
Therefore, there is a need in the art for improved wireless networks that have reduce call set-up time for time-sensitive applications. In particular, there is a need for a CDMA2000 wireless network that provides reduce call set-up times for chat and Push-To-Talk services.